Hydraulic apparatus

ABSTRACT

A hydraulic apparatus including a pair of body members, each having a flat surface, a hydraulic circuit member having two flat parallel surfaces and at least one slot extending in the circuit member between the two parallel flat surfaces, clamping means to hold the body members together with the circuit member clamped between the flat body surfaces, at least one hydraulic component formed on or secured to at least one body member, and ports including at least one port from the component or components. Each port opens into the flat surface of the body member in which it is formed. The arrangement is such that associated ports are connected by a slot in the circuit member which forms a flow passage between the flat surfaces of the pair of body members to carry fluid in a direction parallel to the flat surfaces between the ports.

,[22] Filed:

[ 1 HYDRAULIC APPARATUS [75] Inventor: Robert Albert Gibbins, Cheltenham,

England [73] Assignee: Dowty Mining Equipment Limited,

Tewkesbury, England Oct. 20, 1972 21 Appl. No.: 299,248

[30] Foreign Application Priority Data Oct. 28, 1971 Great Britain 50416/71 [52] US. C1 137/608, 137/799, 137/596.l5 [51] Int. Cl. Fl7d 1/08 [58] Field of Search 137/608, 596.14, 596.15, 137/62548, 596.12, 596.13, 799, 625.67; 61/45 D [56] References Cited UNITED STATES PATENTS 2,684,692 7/1954 Hunter et a1 137/799 X 3,472,261 10/1969 Brannon 137/115 X 3,513,876 5/1970 Tarbox 137/608 X 3,530,884 9/1970 Kutz 137/608 3,547,139 12/1970 Van Berkum 137/833 X 3,556,144 1/1971 Anthony Bickers 137/608 X 3,587,607 6/1971 Konig et a1. 137/833 3,589,387 6/1971 Raymond... 137/608 X 3,623,501 11/1971 Reimbold l37/355.17

[ 51 Oct. 8, 1974 Primary Examiner-J-lenry T. Klinksiek Attorney, Agent, or Firm-Young and Thompson [5 7] ABSTRACT A hydraulic apparatus including a pair of body members, each having a flat surface, a hydraulic circuit member having two flat parallel surfaces and at least one slot extending in the circuit member between the two parallel flat surfaces, clamping means to hold the body members together with the circuit member clamped between the flat body surfaces, at least one hydraulic component formed on or secured to at least one body member, and ports including at least one port from the component or components. Each port opens into the flat surface of the body member in which it is formed. The arrangement is such that asso ciated ports are connected by a slot in the circuit member which forms a flow passage between the flat surfaces of the pair of body members to carry fluid in a direction parallel to the flat surfaces between the ports.

10 Claims, 11 Drawing Figures PATENTEUU" 3,840,047

- SHEET 30F 4 o o 0 o 0 0 1 HYDRAULIC APPARATUS This invention relates to hydraulic apparatus which includes at least one hydraulic component having connections to facilitate flow in a desired manner.

The term hydraulic used in this specification will be taken to refer generally to the use of liquid and/or gas.

In constructing hydraulic apparatus having a number of connections, it is often found convenient to interconnect the connections principally by means of pipes. For many kinds of hydraulic apparatus, for example mining apparatus, a large number of pipes forms a considerable hazard in operation.

It has been proposed to reduce the number of pipes in such hydraulic apparatus by providing a manifold block on to which the component or components are mounted, passages within the block facilitating flow between the connections in a desired manner. The manufacture of a manifold block can be expensive, requiring a plurality of holes to be drilled in the block to form the passages.

The main object of the present invention is to provide a manifold block for carrying one or more hydraulic components in which firstly the drilling of holes has been reduced and simplified and in which secondly, it is possible to effect changes in the hydraulic passages in the block to provide for different or improved function of the component or components.

Where a multiple hydraulic connector of small size forms part of the apparatus, a further object of the invention is to provide means within the block whereby hydraulic passages from the multiple connector may be easily provided within the block to extend to the component or components secured to the block.

In accordance with the present invention, a hydraulic apparatus includes a pair of body members, each having a flat surface, a hydraulic circuit member having two flat parallel surfaces and at least one slot extending in the circuit member between the two parallel flat surfaces, clamping means to hold the body members together with the circuit member clamped between the flat body surfaces, at least one hydraulic component formed on or secured to at least one body member, and ports including at least one port from the component or components, each port opening into the flat surface of the body member in which it is formed, the arrangement being that associated ports are connected by a slot in the circuit member which forms a flow passage between the flat surfaces of the pair of body members to carry fluid in a direction parallel to the flat surfaces between the ports.

The apparatus may include a multiple hydraulic connector formed on or secured to a body member and having ports opening from its connections into the flat surface of the associated body member, and the circuit member may then have a plurality of slots extending from such ports to connect to associated ports. Such slots may diverge as they extend away from the connector ports to the associated ports.

Where some of the components are comprised by pilot operated valves, the hydraulic circuit member may be arranged of comparatively thin sheet material, the slots within the circuit member being arranged to carry small hydraulic flows only for pilot operation of the valves.

One embodiment of the invention for use with a long-. wall mining apparatus will now be described with reference to the accompanying drawings, in which FIG. 1 is a diagrammatic illustration of the longwall mining apparatus,

FIG. 2 is a circuit diagram of the hydraulic apparatus associated with one roof support of the many roof sup ports shown in FIG. 1,

FIGS. 3 and 4 are respectively side and front elevations of a manifold block having components mounted thereon and forming part of a roof support,

FIG. 5 is a diagrammatic view of a selector valve and its flexible hose connection to the manifold block shown in FIGS. 3 and 4,

FIGS. 6 and 7 are the co-operating flat surfaces of two body members forming the manifold block,

FIG. 8 is a surface view of a circuit member intended for clamping between the surfaces shown in FIGS. 6 and 7,

FIG. 9 is a cross-sectional detail through a part of the body members and circuit member when assembled, and

FIGS. 10 and 11 are longitudinal cross-sections through two different forms of pilot operated valve forming components secured to the manifold block.

Reference is made initially to FIG. 1 which diagrammatically illustrates the longwall mining machine. The general arrangement of the machine is well-known and is intended for use against a long working face 1 of an underground coal seam. Adjacent to the face 1, a conveyor 2 is provided along which a coal-cutter 3 is adapted to travel cutting coal from the face 1 and depositing it in the conveyor to be conveyed away from the face. Immediately adjacent to the conveyor 2, a line of roof supports 4 are provided. Each roof support is of well-known form, comprising a floor engaging beam, a roof engaging beam, and a plurality of vertically arranged hydraulically extendible legs between the beams, hydraulic pressure within the legs supporting the roof from the floor. Each roof support is provided with a hydraulic advancing jack 5 extending from its floor beam to the conveyor. The conveyor itself is composed in known manner of a plurality of pans, arranged in line and loosely connected together so that the conveyor is capable of snaking movement in order that it may move up to the new coal face immediately after the cutting machine has passed. For the purpose of advancing the conveyor to the coal face, the advancing jacks are energised hydraulically to push the conveyor, reacting against the floor beams of the roof supports. The advancing jacks of the roof supports 4a shown in FIG. 1 are urging the conveyor 2 in a snaking movement towards the coal face. After the conveyor has been fully advanced to the coal face, the roof supports are released from the roof one at a time and the advancing jack is then contracted to pull the roof support to a new position closely adjacent to the conveyor. The advancing jacks of the roof supports 4b in FIG. 1 have been advanced up to the conveyor by contraction of the advancing jacks. The hydraulic adjustments of the roof supports and their advancing jacks are controlled by miners who are able to move along the line of supports, each roof support including a selector valve for operation by the miner.

Reference is now made to FIG. 2 showing diagrammatically the hydraulic circuit associated with one roof support. The roof support includes six-hydraulically operated telescopic legs arranged in three pairs ll, 12 and 13. Each telescopic leg includes only one working space and for each pair these are connected in parallel to a flexible pipe respectively 14, 15 and 16. Hydraulic connections to the three pipes 14, 15 and 16 are controlled respectively by. three pilot-operated valves 17, 18 and 19. Each pilot-operated valve includes two opposed pilot pistons, hydraulic fluid acting on one piston to move the valve to supply liquid at pressure to the associated legs or alternatively on the other pilot piston to connect the associated legs to drain 10. A pipe 21 connects to the three pilot pistons of the valves 17, 18 and 19 so that a pressure pulse supplied through pipe 21 will urge the three valves 17, 18 and 19 simultaneously to the position to supply liquid at pressure to the six legs. A pipe 22 connects to the three pilot pistons of the valves l7, l8 and 19 so that a pressure pulse in pipe 22 will simultaneously connect the working spaces of the six legs to drain. The pipe 21 extends from a shuttle valve 23 which is capable of receiving liquid at pressure from a pipe 24 extending to the left or from a pipe 25 extending to the right. Similarly, th pipe 22 extends from a shuttle valve 26 capable of receiving liquid at pressure from a pipe 27 extending to the left or a pipe 28 extending to the right.

The advancing jack 5 associated with the floor beam is a double acting jack having two opposed working spaces. For advancing the conveyor from the support liquid at pressure is supplied to one working space of the advancing jack 5 through pipe 29 from a pilotoperated valve 31. In order to contract the jack 5, liquid at pressure is supplied to the other working space through a pipe 32 from a pilot-operated valve 33. The pilot-operating piston of the valve 33 is fed with liquid from the pipe 22, the arrangement being that when hydraulic liquid is supplied to the pipe 22, the legs 11, 12 and 13 will collapse simultaneously with the feeding of liquid to the jack 5 to cause it to contract and to advance the support towards the conveyor.

A selector valve 34 is mounted on each roof support, the selector handle 35 being rotatable to move the valve into any of five different positions. The five positions are indicated by the letters A. B. C. D and E. Associated with the selector valve 34 there are five ports indicated respectively at 36, 37, 38, 39 and 41. The function of the selector valve is to feed liquid at pressure to any one of the ports 36 to 41 in accordance with the selected position A to E of the valve, the remainder of the ports for any one position being connected to the drain connection 42. Hydraulic pressure from the main pressure connection 43 enters through pipe 44, filter 45 and impulse valve 46 to main pressure port 47. The function of the impulse valve is to apply pressure to any one of the selected ports 36 to 41, this being controlled by the miner by depression of the handle 35 after it has been rotated to the selected position. Also within the control valve 34, a push valve 48 is located controlled by a separate handle 49 adjacent to the selector valve handle. The port 38 of the selector valve enters valve 48 and within valve 48 is connectible to a port 51 either by a non-return valve or by a direct connection, the non-return valve being operative when handle 49 is not depressed and the direct connection being operative when handle 49 is depressed. Port 51 connects to a pipe 52 which extends to the pilot piston of valve 31. Valve 48 may also be pilot operated when a pressure pulse appears in pipe 22.

The ports 36 and 37 are connected respectively to pipes 53 and 54 extending to the left in the diagram and the ports 39 and 41 are connected respectively to pipes 55 and 56 extending to the right in the diagram.

When a miner stands under a roof support and operates the handle 35 of the selector valve, he is able to control only the advancing jack 5 of the support under which he stands, by moving the handle 35 to select position C for this purpose. Having selected position C and depressed handle 35 the pulse of pressure passes valve 48 into pipe 42 and is trapped therein by the nonreturn valve. This pilot pressure will operate pilot valve 31 to supply liquid at pressure from main pressure pipe 43 to jack 5 through pipe 29. The pushing operation will continue until the miner operates the handle 49 of valve 48 which will then allow liquid trapped in the pipe 52 to leak back through port 38 to drain 42, thus closing valve 31. When the miner selects position A or position B, the pulse flows of liquid will leave through pipes 53 and 54 for connection to the support to the left of the one under which the miner stands. For position A liquid leaves through pipe 53 and will enter through pipe 25 of the adjacent left support to cause the supply of pressure to the legs to set the support to the roof. If the miner selects position B, the pulse of liquid is supplied to pipe 54 which will enter the adjacent left support through pipe 28 to cause collapse of the telescopic legs and contractions of the jack 5 to advance the support to the conveyor. If the miner selects positions D or E of the valve, control pulses will be supplied to the adjacent right support to cause respectively collapse of that support and contraction of jack 5 or setting of the support against the roof.

The roof beam of each roof support may include a hinged cantilever portion extending over the conveyor. The hinged cantilever portion is controlled by two jacks 57 and 58. The jack 57 will control the angular setting of the cantilever portion of the roof beam relative to the main roof beam whilst the jack 58 will control the lengthwise extension of the cantilever portion relative to the main roof beam. Both jacks are doubleacting. The jack 57 has one working space connected to the pipe 32 which is fed with pressure from pilot valve 33 and is retracted simultaneously with the operation of the three pilot valves 17, 18 and 19 to connect the legs 11, 12 and 13 to drain. Pressure in pipe 32 will retract jack 57.

The other working space of the cantilever jack 57 is connected by means of pipe 59 from a pilot-operated control valve 61. The valve 61 is pilot-operated from the pipe 32 to connect pipe 59 to drain. Valve 61 is manually operated by a manual lever 62 to connect liquid at pressure from pipe 43 to pipe 59 to raise the cantilever. Thus raising of the cantilever is under the manual control of a miner by means of lever 62. When valve 61 is not operated pipe 59 is closed to lock ram 57. One working space of the jack 58 is connected to the pipe 32 and the cantilever will be retracted simultaneously with connection of the legs to drain and contraction of the advancing jack 5. A manually-controlled valve 63 controls flow of liquid through pipe 64 to the other working space of ram 58, the valve 63 being manually-operated when it is desired to extend the cantilever. When the valve 63 is not operated, pipe 64 is connected to drain to ensure that retraction of the cantilever can take place when pressure is fed to the pipe 32.

Spring loaded pressure relief valves 65, 66 and 67 are associated respectively with the pipes 14, and 16 to prevent pressure therein rising above predetermined levels. A pressure relief valve 68 is also associated with the pipe 59 to prevent pressure therein rising above a predetermined level.

Reference is now made to FIGS. 3 and 4 of the accompanying drawings. A manifold block 70 is supported by means of a bracket plate 72 to the underside of the roof beam of each support. The block 70 is principally formed by body member 71. Five valve units are secured by bolts to the surfaces of a body member 71 of the manifold block. Three of these valve units comprise the pilot-operated valves 17, 18 and 19 each being formed as a removable module secured to the surface 73 of the member 71, a gasket 74 being interposed between the modules and the surface 73 to ensure fluid-tight connections between ports in the surfaces. Each of the three modules includes the relief valves 65, 66 and 67 respectively secured thereto. The pilot-operated valves 31 and 33 are secured to another surface 75 of the member 71, a gasket 76 being interposed to ensure fluid tight connection of co-operating ports. A further valve position is available on the surface 75 for another function but in this instance the position is closed by a blanking plate 76. All of the modules and the blanking plate are simply secured in position by means of screw-threaded bolts 78, suitably screw-threaded into the body member 71.

The under surface 79 of member 71 has an auxiliary block 80 secured thereto by bolts, a suitable gasket 81 being interposed to ensure liquid tight connection of ports. The auxiliary block 80 carries two sets of three sockets each of which one set of sockets 82, 83 and 84 is visible in FIG. 3. The socket 82 is the main pressure connection, the socket 83 is the main drain connection and the socket 84 is a multiple socket connection. Flexible hoses are provided for each of the three sockets 82, 83 and 84, such flexible hoses extending to sockets in a similar auxiliary block attached to the main manifold block of the support to the right. The second set of sockets from the subsidiary block 80 of which only one socket 85 is visible in FIG. 4 carry flexible hoses extending to sockets on the auxiliary block of the support to the left. Socket 84 will carry pipes 24, 27, 53, 54 and socket 85 will carry pipes 25, 28, 55, 56. The front surface of the block 80 also conveniently carries the shuttle valves 23 and 26, and the relief valve 68.

The front surface 86 of the body member 71 has an another body member referred to as auxiliary block 87 secured thereto by screws 88, a gasket in the form of a circuit member 89 being interposed between the flat surface 86 of the member 71 and a flat surface 91 of the auxiliary block. The auxiliary block 87 carries a multiple connection socket facing forwardly. The surface 86,the surface 91 and the circuit member 89 are shown in more detail in FIGS. 6, 7 and 8. As shown, the circuit member 89 may be fitted directly on to the surface 91, but the surface 86 as shown in FIG. 6 will be inverted before being placed on top of the circuit member 89. The socket 92 includes at its base ten sockets regularly arranged on a small diameter circle. These sockets include appropriate seals 94 (see FIG. 5) and open into the surface 86 as the small ports 93 arranged on a small diameter circle.

FIG. 5 illustrates the connection of the socket 92 to the remotely-positioned selector valve 34. The valve 34 whose structure is well-known will not be described in detail other than to point out that it includes the control handle 35 as mentioned with reference to FIG. 2

which is adjustable about a central axis AA to select any one of the positions A to E and is depressible to the plane of FIG. 5 to open the pulse valve 46. The selector valve 34 is mounted at any convenient position, preferably at the forward end of the roof beam for operation by the miner. The valve 34 is provided with a multiconnection socket similar to the socket 92. The sockets 95 and 92 are connected together by a flexible hose containing a plurality of small diameter hoses and having at either end a multiple plug connection respectively 97 and 98. Whilst there are 10 small hoses incorporated within hose 96 and connected to the plug connectors 97 and 98 and hence to the sockets 93 opening into the surface 86, eight of these hoses are actually used and comprise pipes 52, 53, 54, 55, 56, 22, 42 and 44. The sockets 93 opening into the surface 86 will make connection with a plurality of diverging slots 99 in the circuit member 89 which in turn connect with various ports 101 opening into the surface 91 of manifold 71. For convenience only one of these slots will be described in detail, this slot being indicated by 102. This slot extends from one of the sockets 93 in surface 86 and connects to a port 103 in surface 91. The slot 102 in fact represents a part of the pipe 52 in FIG. 2 and carries flow of liquid between the control valve 34 and the pilot piston of valve 31. The flow in the slot 102 is between port 103 and the associated socket 93 and will take place parallel to the surfaces of the circuit member 89. The flow capacity of such a slot 102 will clearly depend on the thickness of the sheet material from which the circuit member 89 is formed. In the present instance, it is quite adequate for the sheet from which the circuit member 89 is formed to be of the order of .03 inches in thickness since a small flow only is required for pilot operation of the valve 31.

Within the body member 71, port 103 connects by a simple drilled passage to the pilot-operated valve 31, such drilled passage extending from the surface 86 to the surface 75.

The circuit member 89 includes other slots for carrying hydraulic flows other than those associated with the multiple sockets 93.

Where a slot in the circuit member 89 is intended to carry liquid at high pressure and the slot is of considerable length, the problem can arise that the side thrust exerted on the sides of the slot of the circuit member can be sufficient to distort the circuit member or possibly eject part of the circuit member from the associated connecting surfaces. This difficulty is prevented in accordance with a further feature of the present invention. In the circuit member 89 there is a requirement that four ports 104 should all be inter-connected to carry liquid at high pressure. For this purpose a plurality of slots 105 are formed in end to end relation, parts 106 of the sheet material remaining between the adjacent ends of the slots. Adjacent each part 106 a dimple 107 is formed in the associated surface 86of the auxiliary block 87, the dimples 107 then forming connections between the adjacent ends of the slots 105. The parts 106 of the circuit member thus form reinforcing webs between the sides of the long slot carrying liquid at high pressure. The slots 105 shown in FIG. 8 form part of the pipe 21 of FIG. 2, some of the ports 104 being connected by drillings in the manifold block to appropriate ports in the surface 73 of the body member 71 for connection to the pilot-operated valve 17, 18 and 19 for pilot operation thereof. One of the ports 104 will connect by suitable drillings from the shuttle valve 23 mounted on the auxiliary block 80. In FIG. 4 member 87 is shown broken away to show the location of the circuit member 89 between surfaces 86 and 91.

To effect suitable sealing of the slots within the circuit member 89, strips of sealing material indicated at 108 are adhesively secured around the slots 99, 102 and 105 on both surfaces of the circuit member 89. Such material may be applied in the manner set out in US. Patent No: 3,477,867.

In arranging the slots in the circuit member 89, it is possible that such slots will be non-symmetrically placed having regard to the holding bolts 88 which extend through holes 109 in the circuit member. The resulting non-symmetrical distribution of the sealing strips 108 could result in distortion of the auxiliary block 87 when the bolts 88 are suitably tightened. To prevent such distortion auxiliary strips 111 of sealing material are deposited on the surfaces of the circuit member at positions where there are no slots. in this way, the bolts 88 may be tightened down on to the auxiliary block 87 with equal loading and the compressing force exerted by the block on the circuit member 89 will not tend to distort the block 87.

Each of the two valves 31 and 33 may take the form indicated in FIG. 10. The main body of the valve is provided with a flat surface 113 to engage the surface 75 of the body member 71 and into this surface main pressure and return ports 114 and 115 are located together with a pilot port 116. The body 112 includes a separate socket connection 117 into which a pipe 29 or 32 is connected, each such pipe being in the form of a flexible hose. Within the valve the pilot port 116 extends to a pilot piston. The pressure and return ports 114 and 115 are alternatively connected to the socket 117 by the movement of valve members 119 and 121 relatively to their seats respectively 122 and 123. Spring loading 124 ensures that valve member 119 is seated in the absence of pilot pressure acting on pilot piston 118, thus isolating the pressure supply from the socket 117 when no pilot pressure acts through port 116.

FIG. 11 illustrates the construction of any one of the pilot-operated valves 17, 18 or 19. Such a valve comprises a body 125 having a flat surface 126 into which open the main pressure port 127, the main return port 128, and a pair of pilot ports 129 and 131. The body 125 is also formed with an output socket adapted to receive the end of a flexible hose extending to the associated pair of legs in the support. Within the body 125, a pair of opposed pilot pistons 133 and 134 are provided acting respectively on valve members 135 and 136. These valve members co-operate with seats 137 and 138. Pilot pressure supplied through connection 129 will lift valve member 135 from seat 137, thus allowing pressure from port 127 to flow to socket 132. Pilot pressure acting on piston 134 will lift valve member 136 from seat 138 to permit liquid from socket 132 to return to drain. The body 125 also encloses a pressure relief valve unit 139 capable of venting liquid at pressure from socket 132 back to the port 128 when pressure in the socket rises above a predetermined value.

The gasket 81 secured between the body member 71 and the auxiliary block 80 may also include slots which co-operate with ports in the adjacent body member surfaces to provide for connection of the sockets within couplings 84 and to appropriate components carried by body member 71.

The five pilot-operated valves are so provided that each pilot-operated piston may be manually-operated in an emergency. Thus each pilot piston has a plunger 141 adjacent thereto which may be depressed by the insertion of a suitable lever in a transverse passage 142 provided in the associated valve body.

Whilst the invention has been described with reference to an underground mining machine, it will be appreciated that the invention may be applied to any hydraulic apparatus where there are a number of hydraulic components which need to be hydraulically interconnected in a predetermined manner. It will also be appreciated that by suitable arrangement of the ports in the associated body members alternative circuit members may be introduced to provide different interconnections between the hydraulic components in order to provide improved or modified function of the whole hydraulic apparatus.

I claim:

1. A hydraulic apparatus including a pair of body members each having a flat surface, a hydraulic circuit member having two flat parallel surfaces, a plurality of slots in the circuit member each opening along its length to the two parallel flat surfaces, clamping means to hold the body members together with the circuit member clamped between the flat body surfaces, at

least on pilot-operated valve formed on or secured to a body member, at least one port connected to carry pilot fluid for pilot operation of the pilot-operated valve, such port opening to the flat surface of the associated body member, a multiple hydraulic connector formed on or secured to a body member, a plurality of connections within the connector each having a port opening into the flat surface of the associated body member, the slots in the circuit member being each arranged to connect together ports in the flat surfaces, and to carry fluid in a direction parallel to the flat surfaces, at least one slot being arranged to carry fluid for pilot operation of the pilot-operated valve.

2. A hydraulic apparatus as claimed in claim 1 arranged so that the slots diverge as they extend away from the connector ports to the associated ports.

3. A hydraulic apparatus as claimed in claim 2 including a selector valve connected with the multiple hydraulic connector for controlling fluid flow within the connections thereof and including control of said pilot flow.

4. A hydraulic apparatus as claimed in claim 2 wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part thereof being permanently attached to its associated body member.

5. A hydraulic apparatus as claimed in claim 4 including a plurality of flexible hoses extending from the other part of the multiple hydraulic connector.

6. A hydraulic apparatus as claimed in claim 1 including a selector valve connected with the multiple hydraulic connector for controlling fluid flow within the connections thereof and including control of said pilot flow.

7. A hydraulic apparatus as claimed in claim 6 wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part thereof being permanently attached to its associated body member.

10. A hydraulic apparatus as claimed in claim 9 including a plurality of flexible hoses extending from the other part of the multiple hydraulic connector. 

1. A hydraulic apparatus including a pair of body members each having a flat surface, a hydraulic circuit member having two flat parallel surfaces, a plurality of slots in the circuit member each opening along its length to the two parallel flat surfaces, clamping means to hold the body members together with the circuit member clamped between the flat body surfaces, at least on pilotoperated valve formed on or secured to a body member, at least one port connected to carry pilot fluid for pilot operation of the pilot-operated valve, such port opening to the flat surface oF the associated body member, a multiple hydraulic connector formed on or secured to a body member, a plurality of connections within the connector each having a port opening into the flat surface of the associated body member, the slots in the circuit member being each arranged to connect together ports in the flat surfaces, and to carry fluid in a direction parallel to the flat surfaces, at least one slot being arranged to carry fluid for pilot operation of the pilot-operated valve.
 2. A hydraulic apparatus as claimed in claim 1 arranged so that the slots diverge as they extend away from the connector ports to the associated ports.
 3. A hydraulic apparatus as claimed in claim 2 including a selector valve connected with the multiple hydraulic connector for controlling fluid flow within the connections thereof and including control of said pilot flow.
 4. A hydraulic apparatus as claimed in claim 2 wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part thereof being permanently attached to its associated body member.
 5. A hydraulic apparatus as claimed in claim 4 including a plurality of flexible hoses extending from the other part of the multiple hydraulic connector.
 6. A hydraulic apparatus as claimed in claim 1 including a selector valve connected with the multiple hydraulic connector for controlling fluid flow within the connections thereof and including control of said pilot flow.
 7. A hydraulic apparatus as claimed in claim 6 wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part thereof being permanently attached to its associated body member and the other part being attached to the selector valve.
 8. A hydraulic apparatus as claimed in claim 7 including a plurality of flexible hoses extending from said other part of the multiple hydraulic connector to the selector valve.
 9. A hydraulic apparatus as claimed in claim 1 wherein said multiple hydraulic connector is formed in two parts detachable one from the other, one part thereof being permanently attached to its associated body member.
 10. A hydraulic apparatus as claimed in claim 9 including a plurality of flexible hoses extending from the other part of the multiple hydraulic connector. 